Intrinsic Aids to interpretation are found within the act itself. The judge may use other parts of the Act to understand the meaning of the word or phrase in question. These are long/short title of an Act, Preamble/objectives/purposes section, schedules, definition section and punctuation.
Long/short title may be used as a guidance for the judge to find the true meaning of an Act. For example, the long title of the Abortion Act 1967 is 'An Act to amend and clarify the law relating to termination of pregnancy by registered medical practitioners.' This was referred to by four of the five Law Lords who heard the appeal in Royal College of Nursing of the United Kingdom v DHSS (1981).
The preamble/objectives/purposes section that can be found at the beginning of an Act. A preamble is usually found in older statuses and it is a statement preceding the main body of the Act, setting out the purpose of the Act in detail. The objectives/purposes section is usually found at the beginning of the newer acts.
The schedules appear as additions to the main body of the Act. These are usually referred by judges to make some sense of the main text. In some cases it is necessary to look at the Schedules in order to fully understand the Act. For example s2(1) of the Hunting Act 2004 provides 'Hunting is exempt if it is within a class specified in Schedule 1.' The exempt classes of hunting are then specified in Schedule 1.
Judges can also refer to the definition section that most modern Acts contain. This section contains definitions of key words used in the Act to help judges understand the meaning of an Act.
The punctuation is also considered as an intrinsic aid as it can have an effect on the meaning of words and can be taken into account in determining the meaning of statutory provisions. In Hanlon v The Law Society (1981) Lord Lowry said: ' I consider that not to take account of punctuation disregards the reality that literate people, such as parliamentary draftsmen, punctuate what they write, if not identically, at least in accordance with grammatical principles. Why should not literate people, such as judges, look at the punctuation in order to interpret the meaning of the legislation as accepted by Parliament.'
Extrinsic Aids are materials found outside the Act that may be referred to by the judge. These are dictionaries, previous acts, Interpretation Act (1978), Reports of Law Reform bodies, Hansard, International Treaties, Explanatory notes and textbooks.
A dictionary is considered as an extrinsic aid, as it can be used to find the literal meaning of words. For example, in Vaughan v Vaughan (1973) the Court of Appeal had to interpret the word 'molest'. The defendant had been the subject of injunctions in respect of previous violence towards his ex-wife, who was afraid of him.The defendant argued that pestering his ex-wife to resume their relationship by going to her home early in the morning and late at night, and also calling on her at work did not amount to molesting her. The judges decided to look into the dictionary which defined 'molest' as to 'cause trouble, vex, annoy, or put to inconvenience' and held that the defendant's behaviour did amount to molestation.
Previous Acts are considered as extrinsic aids as they may be referred to by judges. For example, in Wheatley (1979) the Court of Appeal had to interpret the provisions of the Explosive Substances Act 1883. The long title of the Act was 'An Act to amend the law relating to explosive substances, amending the Explosives Act 1875.' The Court of Appeal therefore looked at the earlier Act to made sense of the 1883 Act.
The Interpretation Act 1978 provides definition of certain words which are often used in Acts to help judges understand the meaning and purpose of an Act. For example it provides that masculine shall include the feminine and singular words include the plural unless a contrary intention appears within an Act.
Reports of the Law Commission, Royal Commissions and other official law reform bodies are also considered as extrinsic aids. Those reports are important because they can highlight what is wrong with the old law and suggest options. A report usually includes a draft Bill.
International Treaties may also be referred to by judges in order to ascertain the overriding objective of the Treaty which the Act is intended to comply with. This extrinsic aid is very often used by judges interpreting EU law.
Hansard is also one of the extrinsic aids. Since Pepper (Inspector of Taxes) v Hart (1993) the courts have been able to refer to the Parliamentary debates recorded in Hansard. However the House of Lords in this case held that Hansard can only be referred to in certain circumstances : 'The Act must be ambiguous or obscure, or a literal interpretation would lead to an absurdity. Judges may look only at statements made by a Minister or other promoter of the Bill. The statements must be clear in order for them to be relied upon.'
Explanatory notes are written by the Government department responsible for the Act once the Act has been given Royal Assent. Since 1999 Acts have been issued with explanatory notes. These are not part of the Act and therefore are considered as extrinsic aids rather than intrinsic aids.
Textbooks are also considered as extrinsic aids, as they may be referred to for guidance as to the meaning of a word or phrase. For example, in Re Castioni (1891) J.F. Stephen referred to his own text, History of the criminal Law of England, when interpreting the words 'political crime'.